xref: /petsc/src/dm/impls/patch/patch.c (revision f97672e55eacc8688507b9471cd7ec2664d7f203)
1 #include <petsc/private/dmpatchimpl.h>   /*I      "petscdmpatch.h"   I*/
2 #include <petscdmda.h>
3 #include <petscsf.h>
4 
5 /*
6 Solver loop to update \tau:
7 
8   DMZoom(dmc, &dmz)
9   DMRefine(dmz, &dmf),
10   Scatter Xcoarse -> Xzoom,
11   Interpolate Xzoom -> Xfine (note that this may be on subcomms),
12   Smooth Xfine using two-step smoother
13     normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine
14   Compute residual Rfine
15   Restrict Rfine to Rzoom_restricted
16   Scatter Rzoom_restricted -> Rcoarse_restricted
17   Compute global residual Rcoarse
18   TauCoarse = Rcoarse - Rcoarse_restricted
19 */
20 
21 /*@C
22   DMPatchZoom - Create patches of a DMDA on subsets of processes, indicated by commz
23 
24   Collective on dm
25 
26   Input Parameters:
27 + dm - the DM
28 . lower - the lower left corner of the requested patch
29 . upper - the upper right corner of the requested patch
30 - commz - the new communicator for the patch, MPI_COMM_NULL indicates that the given rank will not own a patch
31 
32   Output Parameters:
33 + dmz  - the patch DM
34 . sfz  - the PetscSF mapping the patch+halo to the zoomed version (optional)
35 - sfzr - the PetscSF mapping the patch to the restricted zoomed version
36 
37   Level: intermediate
38 
39 .seealso: `DMPatchSolve()`, `DMDACreatePatchIS()`
40 @*/
41 PetscErrorCode DMPatchZoom(DM dm, MatStencil lower, MatStencil upper, MPI_Comm commz, DM *dmz, PetscSF *sfz, PetscSF *sfzr)
42 {
43   DMDAStencilType st;
44   MatStencil      blower, bupper, loclower, locupper;
45   IS              is;
46   const PetscInt  *ranges, *indices;
47   PetscInt        *localPoints  = NULL;
48   PetscSFNode     *remotePoints = NULL;
49   PetscInt        dim, dof;
50   PetscInt        M, N, P, rM, rN, rP, halo = 1, sxb, syb, szb, sxr, syr, szr, exr, eyr, ezr, mxb, myb, mzb, i, j, k, l, q;
51   PetscMPIInt     size;
52   PetscBool       patchis_offproc = PETSC_TRUE;
53   Vec             X;
54 
55   PetscFunctionBegin;
56   if (!sfz) halo = 0;
57   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
58   /* Create patch DM */
59   PetscCall(DMDAGetInfo(dm, &dim, &M, &N, &P, NULL,NULL,NULL, &dof, NULL,NULL,NULL,NULL, &st));
60 
61   /* Get piece for rank r, expanded by halo */
62   bupper.i = PetscMin(M, upper.i + halo); blower.i = PetscMax(lower.i - halo, 0);
63   bupper.j = PetscMin(N, upper.j + halo); blower.j = PetscMax(lower.j - halo, 0);
64   bupper.k = PetscMin(P, upper.k + halo); blower.k = PetscMax(lower.k - halo, 0);
65   rM       = bupper.i - blower.i;
66   rN       = bupper.j - blower.j;
67   rP       = bupper.k - blower.k;
68 
69   if (commz != MPI_COMM_NULL) {
70     PetscCall(DMDACreate(commz, dmz));
71     PetscCall(DMSetDimension(*dmz, dim));
72     PetscCall(DMDASetSizes(*dmz, rM, rN, rP));
73     PetscCall(DMDASetNumProcs(*dmz, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE));
74     PetscCall(DMDASetBoundaryType(*dmz, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE));
75     PetscCall(DMDASetDof(*dmz, dof));
76     PetscCall(DMDASetStencilType(*dmz, st));
77     PetscCall(DMDASetStencilWidth(*dmz, 0));
78     PetscCall(DMDASetOwnershipRanges(*dmz, NULL, NULL, NULL));
79     PetscCall(DMSetFromOptions(*dmz));
80     PetscCall(DMSetUp(*dmz));
81     PetscCall(DMDAGetCorners(*dmz, &sxb, &syb, &szb, &mxb, &myb, &mzb));
82     sxr  = PetscMax(sxb,     lower.i - blower.i);
83     syr  = PetscMax(syb,     lower.j - blower.j);
84     szr  = PetscMax(szb,     lower.k - blower.k);
85     exr  = PetscMin(sxb+mxb, upper.i - blower.i);
86     eyr  = PetscMin(syb+myb, upper.j - blower.j);
87     ezr  = PetscMin(szb+mzb, upper.k - blower.k);
88     PetscCall(PetscMalloc2(dof*rM*rN*PetscMax(rP,1),&localPoints,dof*rM*rN*PetscMax(rP,1),&remotePoints));
89   } else {
90     sxr = syr = szr = exr = eyr = ezr = sxb = syb = szb = mxb = myb = mzb = 0;
91   }
92 
93   /* Create SF for restricted map */
94   PetscCall(DMCreateGlobalVector(dm,&X));
95   PetscCall(VecGetOwnershipRanges(X,&ranges));
96 
97   loclower.i = blower.i + sxr; locupper.i = blower.i + exr;
98   loclower.j = blower.j + syr; locupper.j = blower.j + eyr;
99   loclower.k = blower.k + szr; locupper.k = blower.k + ezr;
100 
101   PetscCall(DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc));
102   PetscCall(ISGetIndices(is, &indices));
103 
104   if (dim < 3) {mzb = 1; ezr = 1;}
105   q = 0;
106   for (k = szb; k < szb+mzb; ++k) {
107     if ((k < szr) || (k >= ezr)) continue;
108     for (j = syb; j < syb+myb; ++j) {
109       if ((j < syr) || (j >= eyr)) continue;
110       for (i = sxb; i < sxb+mxb; ++i) {
111         for (l=0; l<dof; l++) {
112           const PetscInt lp = l + dof*(((k-szb)*rN + (j-syb))*rM + i-sxb);
113           PetscInt       r;
114 
115           if ((i < sxr) || (i >= exr)) continue;
116           localPoints[q]        = lp;
117           PetscCall(PetscFindInt(indices[q], size+1, ranges, &r));
118 
119           remotePoints[q].rank  = r < 0 ? -(r+1) - 1 : r;
120           remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
121           ++q;
122         }
123       }
124     }
125   }
126   PetscCall(ISRestoreIndices(is, &indices));
127   PetscCall(ISDestroy(&is));
128   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), sfzr));
129   PetscCall(PetscObjectSetName((PetscObject) *sfzr, "Restricted Map"));
130   PetscCall(PetscSFSetGraph(*sfzr, dof*M*N*P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES));
131 
132   if (sfz) {
133     /* Create SF for buffered map */
134     loclower.i = blower.i + sxb; locupper.i = blower.i + sxb+mxb;
135     loclower.j = blower.j + syb; locupper.j = blower.j + syb+myb;
136     loclower.k = blower.k + szb; locupper.k = blower.k + szb+mzb;
137 
138     PetscCall(DMDACreatePatchIS(dm, &loclower, &locupper, &is, patchis_offproc));
139     PetscCall(ISGetIndices(is, &indices));
140 
141     q = 0;
142     for (k = szb; k < szb+mzb; ++k) {
143       for (j = syb; j < syb+myb; ++j) {
144         for (i = sxb; i < sxb+mxb; ++i, ++q) {
145           PetscInt r;
146 
147           localPoints[q]        = q;
148           PetscCall(PetscFindInt(indices[q], size+1, ranges, &r));
149           remotePoints[q].rank  = r < 0 ? -(r+1) - 1 : r;
150           remotePoints[q].index = indices[q] - ranges[remotePoints[q].rank];
151         }
152       }
153     }
154     PetscCall(ISRestoreIndices(is, &indices));
155     PetscCall(ISDestroy(&is));
156     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), sfz));
157     PetscCall(PetscObjectSetName((PetscObject) *sfz, "Buffered Map"));
158     PetscCall(PetscSFSetGraph(*sfz, M*N*P, q, localPoints, PETSC_COPY_VALUES, remotePoints, PETSC_COPY_VALUES));
159   }
160 
161   PetscCall(VecDestroy(&X));
162   PetscCall(PetscFree2(localPoints, remotePoints));
163   PetscFunctionReturn(0);
164 }
165 
166 typedef enum {PATCH_COMM_TYPE_WORLD = 0, PATCH_COMM_TYPE_SELF = 1} PatchCommType;
167 
168 PetscErrorCode DMPatchSolve(DM dm)
169 {
170   MPI_Comm       comm;
171   MPI_Comm       commz;
172   DM             dmc;
173   PetscSF        sfz, sfzr;
174   Vec            XC;
175   MatStencil     patchSize, commSize, gridRank, lower, upper;
176   PetscInt       M, N, P, i, j, k, l, m, n, p = 0;
177   PetscMPIInt    rank, size;
178   PetscInt       debug = 0;
179 
180   PetscFunctionBegin;
181   PetscCall(PetscObjectGetComm((PetscObject)dm,&comm));
182   PetscCallMPI(MPI_Comm_rank(comm, &rank));
183   PetscCallMPI(MPI_Comm_size(comm, &size));
184   PetscCall(DMPatchGetCoarse(dm, &dmc));
185   PetscCall(DMPatchGetPatchSize(dm, &patchSize));
186   PetscCall(DMPatchGetCommSize(dm, &commSize));
187   PetscCall(DMPatchGetCommSize(dm, &commSize));
188   PetscCall(DMGetGlobalVector(dmc, &XC));
189   PetscCall(DMDAGetInfo(dmc, NULL, &M, &N, &P, &l, &m, &n, NULL,NULL,NULL,NULL,NULL,NULL));
190   M    = PetscMax(M, 1); l = PetscMax(l, 1);
191   N    = PetscMax(N, 1); m = PetscMax(m, 1);
192   P    = PetscMax(P, 1); n = PetscMax(n, 1);
193 
194   gridRank.i = rank       % l;
195   gridRank.j = rank/l     % m;
196   gridRank.k = rank/(l*m) % n;
197 
198   if (commSize.i*commSize.j*commSize.k == size || commSize.i*commSize.j*commSize.k == 0) {
199     commSize.i = l; commSize.j = m; commSize.k = n;
200     commz      = comm;
201   } else if (commSize.i*commSize.j*commSize.k == 1) {
202     commz = PETSC_COMM_SELF;
203   } else {
204     const PetscMPIInt newComm = ((gridRank.k/commSize.k)*(m/commSize.j) + gridRank.j/commSize.j)*(l/commSize.i) + (gridRank.i/commSize.i);
205     const PetscMPIInt newRank = ((gridRank.k%commSize.k)*commSize.j     + gridRank.j%commSize.j)*commSize.i     + (gridRank.i%commSize.i);
206 
207     PetscCallMPI(MPI_Comm_split(comm, newComm, newRank, &commz));
208     if (debug) PetscCall(PetscPrintf(PETSC_COMM_SELF, "Rank %d color %d key %d commz %p\n", rank, newComm, newRank, (void*)(MPI_Aint)commz));
209   }
210   /*
211    Assumptions:
212      - patchSize divides gridSize
213      - commSize divides gridSize
214      - commSize divides l,m,n
215    Ignore multiple patches per rank for now
216 
217    Multiple ranks per patch:
218      - l,m,n divides patchSize
219      - commSize divides patchSize
220    */
221   for (k = 0; k < P; k += PetscMax(patchSize.k, 1)) {
222     for (j = 0; j < N; j += PetscMax(patchSize.j, 1)) {
223       for (i = 0; i < M; i += PetscMax(patchSize.i, 1), ++p) {
224         MPI_Comm    commp = MPI_COMM_NULL;
225         DM          dmz   = NULL;
226 #if 0
227         DM          dmf     = NULL;
228         Mat         interpz = NULL;
229 #endif
230         Vec         XZ       = NULL;
231         PetscScalar *xcarray = NULL;
232         PetscScalar *xzarray = NULL;
233 
234         if ((gridRank.k/commSize.k == p/(l/commSize.i * m/commSize.j) % n/commSize.k) &&
235             (gridRank.j/commSize.j == p/(l/commSize.i)                % m/commSize.j) &&
236             (gridRank.i/commSize.i == p                               % l/commSize.i)) {
237           if (debug) PetscCall(PetscPrintf(PETSC_COMM_SELF, "Rank %d is accepting Patch %" PetscInt_FMT "\n", rank, p));
238           commp = commz;
239         }
240         /* Zoom to coarse patch */
241         lower.i = i; lower.j = j; lower.k = k;
242         upper.i = i + patchSize.i; upper.j = j + patchSize.j; upper.k = k + patchSize.k;
243         PetscCall(DMPatchZoom(dmc, lower, upper, commp, &dmz, &sfz, &sfzr));
244         lower.c = 0; /* initialize member, otherwise compiler issues warnings */
245         upper.c = 0; /* initialize member, otherwise compiler issues warnings */
246         if (debug) PetscCall(PetscPrintf(comm, "Patch %" PetscInt_FMT ": (%" PetscInt_FMT ", %" PetscInt_FMT ", %" PetscInt_FMT ")--(%" PetscInt_FMT ", %" PetscInt_FMT ", %" PetscInt_FMT ")\n", p, lower.i, lower.j, lower.k, upper.i, upper.j, upper.k));
247         if (dmz) PetscCall(DMView(dmz, PETSC_VIEWER_STDOUT_(commz)));
248         PetscCall(PetscSFView(sfz,  PETSC_VIEWER_STDOUT_(comm)));
249         PetscCall(PetscSFView(sfzr, PETSC_VIEWER_STDOUT_(comm)));
250         /* Scatter Xcoarse -> Xzoom */
251         if (dmz) PetscCall(DMGetGlobalVector(dmz, &XZ));
252         if (XZ)  PetscCall(VecGetArray(XZ, &xzarray));
253         PetscCall(VecGetArray(XC, &xcarray));
254         PetscCall(PetscSFBcastBegin(sfz, MPIU_SCALAR, xcarray, xzarray,MPI_REPLACE));
255         PetscCall(PetscSFBcastEnd(sfz, MPIU_SCALAR, xcarray, xzarray,MPI_REPLACE));
256         PetscCall(VecRestoreArray(XC, &xcarray));
257         if (XZ)  PetscCall(VecRestoreArray(XZ, &xzarray));
258 #if 0
259         /* Interpolate Xzoom -> Xfine, note that this may be on subcomms */
260         PetscCall(DMRefine(dmz, MPI_COMM_NULL, &dmf));
261         PetscCall(DMCreateInterpolation(dmz, dmf, &interpz, NULL));
262         PetscCall(DMInterpolate(dmz, interpz, dmf));
263         /* Smooth Xfine using two-step smoother, normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine */
264         /* Compute residual Rfine */
265         /* Restrict Rfine to Rzoom_restricted */
266 #endif
267         /* Scatter Rzoom_restricted -> Rcoarse_restricted */
268         if (XZ)  PetscCall(VecGetArray(XZ, &xzarray));
269         PetscCall(VecGetArray(XC, &xcarray));
270         PetscCall(PetscSFReduceBegin(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM));
271         PetscCall(PetscSFReduceEnd(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM));
272         PetscCall(VecRestoreArray(XC, &xcarray));
273         if (XZ)  PetscCall(VecRestoreArray(XZ, &xzarray));
274         if (dmz) PetscCall(DMRestoreGlobalVector(dmz, &XZ));
275         /* Compute global residual Rcoarse */
276         /* TauCoarse = Rcoarse - Rcoarse_restricted */
277 
278         PetscCall(PetscSFDestroy(&sfz));
279         PetscCall(PetscSFDestroy(&sfzr));
280         PetscCall(DMDestroy(&dmz));
281       }
282     }
283   }
284   PetscCall(DMRestoreGlobalVector(dmc, &XC));
285   PetscFunctionReturn(0);
286 }
287 
288 PetscErrorCode DMPatchView_ASCII(DM dm, PetscViewer viewer)
289 {
290   DM_Patch          *mesh = (DM_Patch*) dm->data;
291   PetscViewerFormat format;
292   const char        *name;
293 
294   PetscFunctionBegin;
295   PetscCall(PetscViewerGetFormat(viewer, &format));
296   /* if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) */
297   PetscCall(PetscObjectGetName((PetscObject) dm, &name));
298   PetscCall(PetscViewerASCIIPrintf(viewer, "Patch DM %s\n", name));
299   PetscCall(PetscViewerASCIIPushTab(viewer));
300   PetscCall(PetscViewerASCIIPrintf(viewer, "Coarse DM\n"));
301   PetscCall(DMView(mesh->dmCoarse, viewer));
302   PetscCall(PetscViewerASCIIPopTab(viewer));
303   PetscFunctionReturn(0);
304 }
305 
306 PetscErrorCode DMView_Patch(DM dm, PetscViewer viewer)
307 {
308   PetscBool      iascii, isbinary;
309 
310   PetscFunctionBegin;
311   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
312   PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 2);
313   PetscCall(PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &iascii));
314   PetscCall(PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERBINARY, &isbinary));
315   if (iascii) {
316     PetscCall(DMPatchView_ASCII(dm, viewer));
317   }
318   PetscFunctionReturn(0);
319 }
320 
321 PetscErrorCode DMDestroy_Patch(DM dm)
322 {
323   DM_Patch       *mesh = (DM_Patch*) dm->data;
324 
325   PetscFunctionBegin;
326   if (--mesh->refct > 0) PetscFunctionReturn(0);
327   PetscCall(DMDestroy(&mesh->dmCoarse));
328   /* This was originally freed in DMDestroy(), but that prevents reference counting of backend objects */
329   PetscCall(PetscFree(mesh));
330   PetscFunctionReturn(0);
331 }
332 
333 PetscErrorCode DMSetUp_Patch(DM dm)
334 {
335   DM_Patch       *mesh = (DM_Patch*) dm->data;
336 
337   PetscFunctionBegin;
338   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
339   PetscCall(DMSetUp(mesh->dmCoarse));
340   PetscFunctionReturn(0);
341 }
342 
343 PetscErrorCode DMCreateGlobalVector_Patch(DM dm, Vec *g)
344 {
345   DM_Patch       *mesh = (DM_Patch*) dm->data;
346 
347   PetscFunctionBegin;
348   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
349   PetscCall(DMCreateGlobalVector(mesh->dmCoarse, g));
350   PetscFunctionReturn(0);
351 }
352 
353 PetscErrorCode DMCreateLocalVector_Patch(DM dm, Vec *l)
354 {
355   DM_Patch       *mesh = (DM_Patch*) dm->data;
356 
357   PetscFunctionBegin;
358   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
359   PetscCall(DMCreateLocalVector(mesh->dmCoarse, l));
360   PetscFunctionReturn(0);
361 }
362 
363 PetscErrorCode DMCreateSubDM_Patch(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
364 {
365   SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Tell me to code this");
366 }
367 
368 PetscErrorCode DMPatchGetCoarse(DM dm, DM *dmCoarse)
369 {
370   DM_Patch *mesh = (DM_Patch*) dm->data;
371 
372   PetscFunctionBegin;
373   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
374   *dmCoarse = mesh->dmCoarse;
375   PetscFunctionReturn(0);
376 }
377 
378 PetscErrorCode DMPatchGetPatchSize(DM dm, MatStencil *patchSize)
379 {
380   DM_Patch *mesh = (DM_Patch*) dm->data;
381 
382   PetscFunctionBegin;
383   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
384   PetscValidPointer(patchSize, 2);
385   *patchSize = mesh->patchSize;
386   PetscFunctionReturn(0);
387 }
388 
389 PetscErrorCode DMPatchSetPatchSize(DM dm, MatStencil patchSize)
390 {
391   DM_Patch *mesh = (DM_Patch*) dm->data;
392 
393   PetscFunctionBegin;
394   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
395   mesh->patchSize = patchSize;
396   PetscFunctionReturn(0);
397 }
398 
399 PetscErrorCode DMPatchGetCommSize(DM dm, MatStencil *commSize)
400 {
401   DM_Patch *mesh = (DM_Patch*) dm->data;
402 
403   PetscFunctionBegin;
404   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
405   PetscValidPointer(commSize, 2);
406   *commSize = mesh->commSize;
407   PetscFunctionReturn(0);
408 }
409 
410 PetscErrorCode DMPatchSetCommSize(DM dm, MatStencil commSize)
411 {
412   DM_Patch *mesh = (DM_Patch*) dm->data;
413 
414   PetscFunctionBegin;
415   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
416   mesh->commSize = commSize;
417   PetscFunctionReturn(0);
418 }
419